U.S. Has Protested Aug. 19 Incident Through Diplomatic Channels, Calls It Particularly Aggressive

WASHINGTON—An armed Chinese fighter jet on Tuesday conducted what Pentagon officials described as an unusually dangerous and aggressive midair intercept of a U.S.Navy patrol aircraft during a routine patrol in international airspace.

During the incident, which took place about 135 miles east of Hainan island in the South China Sea, the Chinese fighter made three passes under the U.S. aircraft at close range, and conducted a series of...